Birds & Windows

"During the past winter and early spring, a pair of cardinals have been 'attacking' our house windows -- a male at the rear kitchen window and female at two front ground-level bedroom windows. They obviously think they see a rival bird, but their persistence has amazed me. I would appreciate any suggestions you might have, short of applying outside screens, to alleviate this problem. I'm afraid the birds may eventually injure themselves."
Ah, yes, a sure sign of spring is the repetitious and annoying pitter-patter of birds tapping window panes. Shiny hubcaps and rearview mirrors also sometimes catch their attention. Cardinals and robins are the most common culprits, but over the years I've also had chipping sparrows, towhees and even bluebirds muddying my windows. As days get longer, hormonal changes make birds, especially males (but sometimes even females), aggressive and territorial. Some individuals overreact, perhaps due to a hormone imbalance, and battle their own reflection. This can go on for hours each day and may last the entire breeding season. Usually it lasts just a few weeks. The result is muddy, messy and sometimes even bloody windows and unhappy homeowners.
The solution is to eliminate the reflections. Remove shiny hubcaps. Place paper bags over rearview mirrors while vehicles are parked in the driveway. Windows pose a bigger problem. Solutions include tacking two strings of several feathers to the outside of the window. Loose feathers usually indicate a dead bird, so they may instill fear in wild birds. Purchase a bag of feathers at a craft shop, attach one every 12 inches on a string, then tack two feather strings on the outside of each window under attack. Of course, putting screens on every window (sorry, Bob) is the simplest and most obvious solution.
Another option is the "Bird Screen", a flexible, transparent screen that's removable for easy window cleaning. Though originally designed to protect birds from accidentally flying into windows, the "Bird Screen" is equally effective at preventing birds from battling their reflection.

Vain wagtails get into a flap over car wing mirrors: Residents of a small village have been forced to take drastic measures to protect their cars after they were hit by an outbreak of vanity vandalism - by birds. The situation has become so bad that motorists have taken to making special mittens to cover their wing mirrors. Any mirror left uncovered in Withycombe's main street soon requires cleaning so many locals have saved themselves the labour by sewing special mirror covets for their cars. And the narcissistic culprit has been revealed as a flock of grey wagtails that live beside the local stream. Many birds become obsessed by mirrors at this time of year when they're sorting out their territories in readiness for mating but the situation in the West Somerset village has become just too messy for some proud car owners. 'They'll look at themselves in your wing mirror, then do their business all over it, then fly on to the window ledge of the house to have a go at the glass. It's as if they are saying "look what we've done". 'Many of us just got fed up with cleaning the mirrors, so we made the covers to save the bother.'

Scientific Studies of Window-kills of birds for reading or download. Click picture above for "Window Pain" by David Sibley.